Thermal Effects

Thermal EMF generation and leadwire temperature differences can create significant error signals in strain gage circuits, particularly when high heating or cooling rates are involved. These problems are minimized by keeping thermal masses and jumper wires as symmetrical as possible. Use neat solder joints on all terminals with the same amount of solder on each, and keep all jumper wires the same length from terminal strip to gage. The figure below shows the use of a narrow piece of Mylar tape to mask the center area of a set of terminals. This prevents nonuniform solder spread, and assists in obtaining thermal symmetry.

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